contributed by: lots of MKVIII exp

There is a TSB (97-11-11) for all Mark VIII's to upgrade the 1-2 shift accumulator piston and spring for improved shifting and increased durability. The original accumulator piston side loads in its bore and causes the case bore to become scuffed. Bore scuffing causes premature seal wear and eventual intermediate clutch pressure loss, which leads to problems with the 1-2 shift. Dealers now stock the parts (approximately $12.00 for a new style piston and top spring) and you can do the whole job yourself in under an hour and without removing the valve body. My 97 LSC had 22,000 miles regestered when I changed the piston and and it was already scuffed to the point that the o-ring seal had worn out on one side. The revised piston is a different design, works fine even if the case bore is already scuffed, and should last indefinitely. The part number for all 93to 97 Mark VIIIs for the piston is FZAZ-7F251-AA and the new top spring is light blue part # F75Z-7F284-AA